1. Field of the Invention
The present invention relates to a heat dissipation device, and more particularly to a heat dissipation device having a back plate unit for connecting with a retention module and reinforcing support to an electronic component with which a heat sink of the heat dissipation device engages.
2. Description of Related Art
A heat sink is usually placed in thermal contact with an electronic component such as a central processing unit (CPU), and transfers heat through conduction from the electronic component so as to prevent over-heating of the electronic component. Usually, a heat sink is secured to an electronic component by using a locking device.
U.S. Pat. No. 7,142,430 discloses a heat dissipation device. The heat dissipation device comprises a heat sink and a locking device for securing the heat sink on an electronic component that is mounted on a printed circuit board. The locking device comprises a retention module resting on the printed circuit board, a clip attached to the retention module, and a back plate unit mounted below the printed circuit board. The back plate unit comprises a back plate and a gasket attached on the back plate, wherein the back plate has two opposite latches formed at two lateral sides thereof, and the gasket has a pair of elastic wings connecting each other and a pair of tabs formed at junctions of the wings. Two blocks are attached on the pair of wings of the gasket respectively. In use, the back plate is mounted beneath the printed circuit board by the retention module in such a manner that the pair of tabs of the gasket engage with the latches of the back plate with the blocks pressing upwardly against the printed circuit board, thereby providing a support to the electronic component.
However, pressure exerted by the gasket only acts on the two blocks, which cannot give the electronic component a sufficient and uniform support, whereby the electronic component may be damaged or deform due to the downward pressing force of the heat sink on the electronic component.
What is needed, therefore, is an improved heat dissipation device which can overcome the above problems.